U.S. patent number 8,271,243 [Application Number 12/693,813] was granted by the patent office on 2012-09-18 for system and method of integrating subterranean computer models for oil and gas exploration.
This patent grant is currently assigned to Schlumberger Technology Corporation. Invention is credited to Ian David Bryant, Michael De Lind Van Wijngaarden, John Fuller, Thomas Hantschel, Stephen Alexander Hope, Nikolaos Constantinos Koutsabeloulis, Rodney Laver, Melissa Suman.
United States Patent |
8,271,243 |
Koutsabeloulis , et
al. |
September 18, 2012 |
System and method of integrating subterranean computer models for
oil and gas exploration
Abstract
The invention provides a system and method for integrating
petroleum system and geomechanical computer models for use in oil
and gas exploration. In one embodiment, the invention provides a
petroleum system model capable of analyzing data relating to a
subterranean formation and calculating the geometry and
geochemistry of each layer of the formation through geologic time.
The present invention also provides a geomechanical model in
communication with the petroleum system model such that information
concerning each layer of the subterranean formation may be shared
and cross-referenced as an iterative operation prior to the
analysis of subsequent layers. At each step of the iterative
operation, results are calculated, validated, and cross-referenced
in order to produce improved reliability estimates of petroleum
charge and mechanical seal integrity for the subterranean
formation.
Inventors: |
Koutsabeloulis; Nikolaos
Constantinos (Winkfield-Windsor, GB), Hope; Stephen
Alexander (Staines, GB), Fuller; John (Farnham,
GB), Suman; Melissa (Windsor, GB),
Hantschel; Thomas (Aldenhoven, DE), De Lind Van
Wijngaarden; Michael (Aachen, DE), Bryant; Ian
David (Houston, TX), Laver; Rodney (Crawley Down,
GB) |
Assignee: |
Schlumberger Technology
Corporation (Sugar Land, TX)
|
Family
ID: |
42084195 |
Appl.
No.: |
12/693,813 |
Filed: |
January 26, 2010 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100211367 A1 |
Aug 19, 2010 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61153008 |
Feb 17, 2009 |
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Current U.S.
Class: |
703/6; 702/11;
703/10 |
Current CPC
Class: |
G01V
11/00 (20130101) |
Current International
Class: |
G06G
7/48 (20060101) |
Field of
Search: |
;703/6 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Onaisi et al, "Management of Stress Sensitive Reservoirs Using Two
Coupled Stress-Reservoir Simulation Tools: ECL2VIS and ATH2VIS",
SPE 78512, 2002. cited by examiner .
Tran et al, "New Iterative Coupling Between a Reservoir Simulator
and a Geomechanics Module", SPE 88989, 2004. cited by examiner
.
Baur et al, "Integrating Structural Geology and Petroleum Systems
Modeling-A Pilot Project from Bolivia's Fold and Thrust Belt",
Marine and Petroleum Geology, 26, pp. 573-579, available online
Jan. 15, 2009. cited by examiner .
Settari et al, "Geomechanics in Integrated Reservoir Modeling" OTC
19530, Offshore Technology Conference, May 2008. cited by examiner
.
Rodrigues et al, "Incorporating Geomechanics Into Petroleum
Reservoir Numerical Simulation", SPE 107952, 2007. cited by
examiner .
Kristiansen, et al., "Linking seismic response to geo-mechanics",
Geo ExPro Newsletter; downloaded from the Internet on May 21, 2010
at http://www.geoexpro.com/recentadvances/linkingseismic/ see
paragraph "Linking 4D seismic observations and rock mechanics".
cited by other .
Koutsabeloulis, et al., "Coupled geo-mechanics predicts well
failures", E&P, Nov. 1, 2007, downloaded from the Internet on
May 21, 2010 at http://www.epmag.com/archives/features/764.htm see
whole document. cited by other.
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Primary Examiner: Jacob; Mary C
Attorney, Agent or Firm: Wier; Colin
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This patent application claims priority upon and incorporates by
reference herein, a provisional patent application entitled "Method
and System for Integrating Petroleum System and Geomechanical
Models," filed on Feb. 17, 2009, Ser. No. 61/153,008.
Claims
What is claimed is:
1. A method of modeling a subterranean formation comprising the
steps of: providing a petroleum system model of the subterranean
formation; providing a geomechanical model of the subterranean
formation, the geomechanical model being in communication with the
petroleum system model; applying the petroleum system model to a
first layer of the subterranean formation; the petroleum system
model generating a first set of output data pertaining to the first
layer of the subterranean formation; communicating the first set of
output data to the geomechanical model; applying the geomechanical
model to the first layer of the subterranean formation; the
geomechanical model utilizing at least a portion of the first set
of output data generated by the petroleum system model and
generating a second set of output data pertaining to the first
layer of the subterranean formation; and validating at least a
portion of the first set of output data using at least a portion of
the second set of output data prior to applying the petroleum
system model or the geomechanical model to another layer of the
subterranean formation.
2. The method of claim 1, wherein the first layer comprises the
oldest geologic time step of the subterranean formation.
3. The method of claim 2, further comprising the additional step
of: validating at least a portion of the first set of output data
using at least a portion of the second set of output data through
iteration.
4. The method of claim 3, wherein the first set of output data
further comprises change in porosity data and the second set of
output data further comprises change in volumetric strain data.
5. The method of claim 4, wherein the validation step further
comprises: receiving a user defined tolerance between the change in
porosity data and the change in volumetric strain data; and
applying the user defined tolerance to change in porosity data and
change in volumetric strain.
6. The method of claim 5, further comprising the additional steps
of: if the user defined tolerance is not achieved, communicating
the second set of output data to the petroleum system model; and
re-applying the petroleum system model to the first layer of the
subterranean formation utilizing at least a portion of the second
set of output data until the user defined tolerance is
achieved.
7. The method of claim 6, further comprising the additional steps
of: communicating the second set of output data to the petroleum
system model; and applying the petroleum system model to the first
layer and at least one additional layer of the subterranean
formation, the petroleum system model utilizing at least a portion
of the first set of output data and at least a portion of the
second set of output data.
8. A non-transitory computer-readable storage medium for modeling a
subterranean formation comprising instructions which, when
executed, cause a computing device to: apply a petroleum system
model to a first layer of the subterranean formation; the petroleum
system model generating a first set of output data pertaining to
the first layer of the subterranean formation; communicate the
first set of output data to a geomechanical model; apply the
geomechanical model to the first layer of the subterranean
formation; the geomechanical model utilizing at least a portion of
the first set of output data generated by the petroleum system
model and generating a second set of output data pertaining to the
first layer of the subterranean formation; and validate at least a
portion of the first set of output data using at least a portion of
the second set of output data prior to applying the petroleum
system model or the geomechanical model to another layer of the
subterranean formation.
9. The non-transitory computer-readable storage medium of claim 8,
wherein the first layer comprises the oldest geologic time step of
the subterranean formation.
10. The non-transitory computer-readable storage medium of claim 9,
wherein the instructions, when executed, cause the computing device
to: validate at least a portion of the first set of output data
using at least a portion of the second set of output data through
iteration.
11. The non-transitory computer-readable storage medium of claim
10, wherein the first set of output data further comprises change
in porosity data and the second set of output data further
comprises change in volumetric strain data.
12. The non-transitory computer-readable storage medium of claim
11, wherein the instructions, when executed, cause the computing
device to: receive a user defined tolerance between the change in
porosity data and the change in volumetric strain data; and apply
the user defined tolerance to change in porosity data and change in
volumetric strain.
13. The non-transitory computer-readable storage medium of claim
12, wherein the instructions, when executed, cause the computing
device to: if the user defined tolerance is not achieved,
communicate the second set of output data to the petroleum system
model; and re-apply the petroleum system model to the first layer
of the subterranean formation utilizing at least a portion of the
second set of output data until the user defined tolerance is
achieved.
14. The non-transitory computer-readable storage medium of claim
13, wherein the instructions, when executed, cause the computing
device to: communicate the second set of output data to the
petroleum system model; and apply the petroleum system model to the
first layer and at least one additional layer of the subterranean
formation, the petroleum system model utilizing at least a portion
of the first set of output data and at least a portion of the
second set of output data.
15. A subterranean modeling system comprising: a computer system
having a processor configured to apply a petroleum system model to
a first layer of a subterranean formation; the petroleum system
model generating a first set of output data pertaining to the first
layer of the subterranean formation; communicate the first set of
output data to a geomechanical model; apply the geomechanical model
to the first layer of the subterranean formation; the geomechanical
model utilizing at least a portion of the first set of output data
generated by the petroleum system model and generating a second set
of output data pertaining to the first layer of the subterranean
formation; and validate at least a portion of the first set of
output data using at least a portion of the second set of output
data prior to applying the petroleum system model or the
geomechanical model to another layer of the subterranean
formation.
16. The subterranean modeling system of claim 15, wherein the first
layer comprises the oldest geologic time step of the subterranean
formation.
17. The subterranean modeling system of claim 16, wherein the
processor is configured to: validate at least a portion of the
first set of output data using at least a portion of the second set
of output data through iteration.
18. The subterranean modeling system of claim 17, wherein the first
set of output data further comprises change in porosity data and
the second set of output data further comprises change in
volumetric strain data.
19. The subterranean modeling system of claim 18, wherein the
processor is configured to: receive a user defined tolerance
between the change in porosity data and the change in volumetric
strain data; and apply the user defined tolerance to the change in
porosity data and the change in volumetric strain.
20. The subterranean modeling system of claim 19, wherein the
processor is configured to: if the user defined tolerance is not
achieved, communicate the second set of output data to the
petroleum system model; and re-apply the petroleum system model to
the first layer of the subterranean formation utilizing at least a
portion of the second set of output data until the user defined
tolerance is achieved.
21. The subterranean modeling system of claim 20, wherein the
processor is configured to: communicate the second set of output
data to the petroleum system model; and apply the petroleum system
model to the first layer and at least one additional layer of the
subterranean formation, the petroleum system model utilizing at
least a portion of the first set of output data and at least a
portion of the second set of output data.
Description
FIELD OF THE INVENTION
The present invention relates generally to petroleum exploration
and, more particularly, to systems and methods of integrating
petroleum system and geomechanical computer models.
BACKGROUND OF THE INVENTION
Computer modeling and simulation of subterranean conditions is a
vital component of oil and gas exploration. Petroleum system
modeling, also referred to as "charge modeling," is the analysis of
geological and geophysical data related to the petroleum potential
of a subterranean prospect or play. Petroleum system models may be
1D, 2D, or 3D geologic models covering areas ranging from a single
charge area for a prospect to mega-regional studies of entire
basins.
Petroleum system models can predict if, and how, a reservoir has
been charged with hydrocarbons, including the source and timing of
hydrocarbon generation, migration routes, quantities, and
hydrocarbon type. Petroleum system models include the quantitative
analysis and simulation of geological processes in sedimentary
basins on a geological timescale. It further encompasses geometric
development of the basin, heat and pore water flow modeling with
regard to sediment compaction and basin subsidence or uplift, and
the temperature-controlled chemistry of mineral and organic matter
changes. Petroleum system models may be used to simulate processes
related to the generation, migration, accumulation and loss of oil
and gas, thereby leading to an improved understanding and
predictability of their distribution and properties.
Geomechanics is the science of the way rocks compress, expand and
fracture. Over the geological timescale of a prospect or play,
sediments are deposited, compacted, lithified, and deformed by
tectonic events to produce layers of rocks with highly anisotropic
and nonlinear mechanical characteristics. Where reservoirs exist,
the fluids they contain, the reservoir rocks themselves, and the
formations that surround them form intimately coupled systems.
Geomechanical models use calculated pressure, temperature, and
saturation to calculate the behavior of the formation rock through
geologic time. By relating rock stresses to reservoir properties,
the geomechanical model enables the development of mechanical earth
models that predict the geomechanical behavior of the formation
during production and injection. The removal of hydrocarbons from a
reservoir or the injection of fluids changes the rock stresses and
geomechanics environment, potentially affecting compaction and
subsidence, well and completion integrity, cap-rock and fault-seal
integrity, fracture behavior, thermal recovery, and carbon dioxide
disposal.
There remains a need for a computer modeling system and method that
integrates the functionality of petroleum system modeling and
geomechanical modeling for use in oil and gas exploration.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a system and method for
integrating petroleum system and geomechanical computer models for
use in oil and gas exploration. In one embodiment, the invention
provides a petroleum system model capable of analyzing data
relating to a subterranean formation and calculating the geometry
of each layer of the formation through geologic time. The geometry
of each layer is used to determine the geochemical conditions
present in each layer, i.e., the presence and location of oil and
gas deposits.
The present invention also provides a geomechanical model capable
of interacting with the petroleum system model with respect to each
geologic time step of the formation. In one embodiment, the
geomechanical model is in communication with the petroleum system
model such that data concerning each layer of the subterranean
formation may be shared and cross-referenced as an iterative
operation prior to the analysis of subsequent layers. At each step
of the iterative operation, results are calculated, validated, and
cross-referenced. By cross-referencing results for each layer of
the subterranean formation, improved reliability estimates of
petroleum charge and mechanical seal integrity for geological
features may be produced.
In one embodiment, the present invention utilizes a validation
process applying one or more user-defined convergence thresholds.
If such threshold(s) are not met during analysis of a particular
geometric time step, the analysis of the layer at issue may be
repeated through iteration until the desired convergence is
reached.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the
attendant advantages thereof will be readily obtained as the same
becomes better understood by reference to the following detailed
description when considered in connection with the accompanying
drawings; it being understood that the drawings contained herein
are not necessarily drawn to scale; wherein:
FIG. 1 is a two dimensional representation of an example
subterranean formation.
FIG. 2 is a flowchart diagram illustrating the subterranean
computer model integration process of one embodiment of the present
invention.
FIG. 3 is a component diagram illustrating an example computer
system that may be utilized in conjunction with one embodiment of
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, numerous details are set forth to
provide an understanding of the present invention. However, it will
be understood by those skilled in the art that the present
invention may be practiced without these details and that numerous
variations or modifications from the described embodiments may be
possible. Further, the following description is directed to the
analysis of the first and second layers of the subterranean
formation for ease of understanding. The present invention is not
limited to use in conjunction with the layers described in the
examples below, and may be used in conjunction with any one or more
layers of the formation.
The present invention is herein described as a method of modeling a
subterranean formation, as a computer-readable storage medium for
modeling a subterranean formation, and as a subterranean modeling
system. FIG. 1 provides an example two dimensional representation
of a subterranean formation (12). The subterranean formation, or
subsurface underground, is composed of different layers (14) of
subsurface material deposited, compacted, or otherwise tectonically
deformed or displaced over periods of geological time. Each layer
(14) represents the composition of the formation during a
particular geologic time period. In this example, the youngest
layer (14Y) is usually positioned closest to the surface (14S) of
the subterranean formation (12), while the oldest layer (140) is
usually located at the bottom of the formation.
Geologic representations, such as that of FIG. 1, are generated
using seismic data, well data, and other geologic knowledge
collected with respect to each layer of the subterranean formation
through geologic time, including the predicted location of oil and
gas deposits (16). Such representations are utilized by various
computer modeling programs used in the oil and gas industry.
Referring to FIG. 2, the present invention utilizes at least one
petroleum system model, illustrated by Box (18). One example of a
petroleum system model is PETROMOD.TM. software offered by
Schlumberger. The petroleum system model utilized by the present
invention is capable of analyzing geological and geophysical data
relating to the petroleum potential of a subterranean formation.
Upon receiving input data relating to the subterranean formation,
the petroleum system model assimilates available data concerning
the subterranean formation and calculates horizon geometries
together with changes in vertical stress, pressure, porosity,
density, and temperature for the first layer of the formation, as
illustrated by Boxes (20), (22), and (24). Input data may include
any available data concerning the first layer of the formation
including, but not limited to, seismic data, well data, geologic
data, etc.
In one embodiment, the petroleum system model of the present
invention is first applied to the oldest layer (140) of the
formation. In this example, the oldest layer of the formation is
illustrated at the bottom of FIG. 1. Variables such as temperature,
pressure, density and porosity, among others, are calculated by the
petroleum system model for each layer of the formation. In one
embodiment, the petroleum system model calculates the change in
(represented by the symbol ".DELTA.") vertical stress, pressure,
porosity, density and temperature for each cell of the first layer
of the formation.
Prior to analysis of the next layer of the subterranean formation,
the petroleum system model communicates output data pertaining to
its analysis of the first layer of the formation to a geomechanical
model (27), as illustrated by Box (26). One example of a
geomechanical model is VISAGE.TM. software, also offered by
Schlumberger. The VISAGE.TM. software is described in greater
detail in U.S. patent application Ser. No. 12/548,810, entitled
"Fully Coupled Simulation for Fluid Flow and Geomechanical
Properties in Oilfield Simulation Operations," filed on Aug. 27,
2009, the entirety of which is incorporated by reference
herein.
Output data communicated to the geomechanical model may include all
of the output generated by the petroleum system model relating to
the first layer of the formation, or only a portion thereof.
Further, such data may be provided directly to the geomechanical
model or through one or more storage devices accessible by the
geomechanical and petroleum system model. Upon receipt of the
output data from the petroleum system model, the geomechanical
model derives mechanical and strength properties applicable to the
first layer of the formation using at least a portion of the
petroleum system model output data, as illustrated by Box (28).
Petroleum system models are based on an assumption that the stress
state in a basin is simple, with simplified models for vertical and
horizontal stresses, which are assumed to be principal stresses,
with the vertical stress being determined by the overburden weight.
This approach fails to account for the role of geomechanics in
terms of how horizontal stresses can exert a major influence on
basin processes.
In one embodiment, the mechanical properties derived by the
geomechanical model include, but are not limited to, Young's
Modulus and Poisson's Ratio, and strength properties include, but
are not limited to, friction angle and cohesion. The derived
mechanical and strength properties of the formation are used by the
geomechanical model to calculate stress and strain variations
associated with the first layer of the subterranean formation. In
one embodiment, the geomechanical model may utilize uniaxial,
triaxial, Brazilian and Scratch tests, as well as log data together
with measured or computed Young's moduli and Poissons ratios, to
compute stress and strain for each layer of the formation.
The geomechanical model of the present invention utilizes the
derived mechanical and strength properties to perform additional
geomechanical calculations pertaining to the first layer of the
formation, as illustrated by Box (30) of FIG. 2. In one embodiment,
output data generated by the geomechanical model at this step
includes stress and strain variation values for each cell of the
formation of the first layer, as illustrated by Box (32). In one
embodiment, the geomechanical model calculates the change in
(represented by the symbol ".DELTA.") stress and strain for each
cell of the first layer of the formation.
In one embodiment, the present invention validates and
cross-references data generated by both models, i.e., petroleum
system and geomechanical, for each layer of the formation. By
cross-referencing results for each layer of the formation, improved
reliability estimates of petroleum charge and mechanical seal
integrity for geological features may be produced. In one
embodiment, the validation process utilized by the present
invention includes the use of one or more convergence thresholds.
Convergence thresholds are used to increase the reliability and
accuracy of computer simulation data relating to each layer of the
formation.
If such threshold(s) are not met during analysis of a layer of the
formation, the analysis of the layer at issue may be repeated
through iteration until the desired convergence is reached. Such
thresholds may be pre-programmed into the system or entered by one
or more users (34U). In one embodiment, the present invention
determines whether a user defined convergence threshold has been
provided to the system, as illustrated by Box (34).
If no user defined threshold is provided, the present invention may
retrieve "default" or pre-programmed threshold value(s) as
illustrated by Box (36). If a user-defined threshold is available,
the threshold is retrieved by the system, as illustrated by Box
(38). Threshold values may take the form of any suitable value or
variation and may be entered by the user or pre-programmed into the
system. In one embodiment, a percentage variance (%) is utilized to
determine if the desired convergence has been reached.
Once received, thresholds are applied and data from both models is
cross referenced in order to validate the data with respect to the
first layer of the formation prior to analysis of subsequent
layers, as illustrated by Boxes (40) and (42). In one embodiment,
the present invention compares change in porosity values generated
by the petroleum system model to change in volumetric strain values
generated by the geomechanical model in order to determine if the
desired convergence has been achieved.
In this example, if the change in porosity values generated by the
petroleum system model do not converge with the change in
volumetric strain values generated by the geomechanical model
within the desired threshold(s), the analysis of the layer is
repeated through iteration until the desired convergence is
reached, as illustrated by Boxes (44) and (46). In this example,
the combined data generated by the petroleum system model and the
geomechanical model is returned to the petroleum system model for
use in re-analyzing the first layer of the formation in an effort
to improve convergence between the two models.
In one embodiment, the results of the validation process may be
displayed to the user upon a display device. This feature of the
present invention readily informs the user of the validation, or
lack thereof, and also allows the user to amend or revise the
threshold(s) used by the system.
A maximum number of iterations for each layer, in the event of
unacceptable convergence, may be pre-programmed into the system or
entered into the system by the user. For example, the maximum
number of iterations for the first layer of the formation may be
set to four (4) iterations. In this example, if the desired
convergence is not reached after four iterations, the system would
proceed to analyze subsequent layers of the formation even though
the desired convergence is not achieved.
It should be noted that more sophisticated standards may be
implemented to improve or accelerate the convergence through
iteration. For example, the iterative process of the present
invention may be accelerated using Atkins accelerator programs.
When the desired convergence is reached, the combined data
generated by the petroleum system model and the geomechanical model
is returned to the petroleum system model, as illustrated by Box
(48). The data is then used by the petroleum system model to
analyze another layer of the formation, as illustrated by Box (50).
The analysis and validation process described above is then
repeated for the second layer of the formation and so on until all
layers of the formation have been analyzed by the petroleum system
and geomechanical model, as illustrated by Box (52).
The present invention may be implemented on virtually any type of
computer regardless of the platform being used. Referring to FIG.
3, a computer system (54) includes a processor (56), associated
memory (58), a storage device (60), and numerous other elements and
functionalities typical of modern computers (not shown). The
computer (54) may also include input devices, such as a keyboard
(62) and a mouse (64), and output devices, such as a display
monitor (66). The computer system (54) may be connected to a local
area network (LAN) or a wide area network (e.g., the Internet) (68)
via a network interface connection (not shown). Those skilled in
the art will appreciate that these input and output devices may
take other forms, now known or later developed. Further, those
skilled in the art will appreciate that one or more elements of the
aforementioned computer system (54) may be located at a remote
location and connected to the other elements over a network.
The invention may be implemented on a distributed system having a
plurality of individual computer systems, where each portion of the
invention may be located on a different system within the
distributed system. The present invention may also be implemented
upon a hand-held or other portable computing device. Further,
software instructions to perform embodiments of the invention may
be stored on a computer readable medium such as a compact disc
(CD), DVD, diskette, tape, file, hard drive, flash drive, SD memory
card, or any other suitable computer readable storage device.
While various embodiments of the present invention for integrating
petroleum systems and geomechanical earth models are described with
reference to facilitating the exploration phase of hydrocarbon
recovery, it is understood by those skilled in the art that other
embodiments of systems and methods for petroleum system and
geomechanical model integration may be used for facilitation of
decision making in other phases of recovery as well (e.g., drilling
and production).
Although the invention has been described with reference to
specific embodiments, this description is not meant to be construed
in a limited sense. Various modifications of the disclosed
embodiments, as well as alternative embodiments of the invention,
will become apparent to persons skilled in the art upon reference
to the description of the invention. It is, therefore, contemplated
that the appended claims will cover such modifications that fall
within the scope of the invention.
* * * * *
References